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The 3 Agent Types on heyadmin.ai: Voice, Video, and Chat — Which One Do You Need?

Team·September 3, 2026·12 min read
The 3 Agent Types on heyadmin.ai: Voice, Video, and Chat — Which One Do You Need?

Introduction

When you create your first AI agent on heyadmin.ai, the first decision you'll make is: Which agent type do I need?

Voice? Video? Chat?

Each has distinct strengths. This guide walks you through all three, explains how they work under the hood, and helps you pick the right one for your use case.


Quick Comparison: The 3 Agent Types

Feature

Voice

Video

Chat

Input Method

Microphone (audio)

Microphone + webcam

Text keyboard

Output

AI voice reply (audio)

Lip-synced avatar (video + audio)

Streaming text

Protocol

WebSocket + audio codec

WebSocket + video codec (D-ID WebRTC)

WebSocket (text-only)

STT (Speech-to-Text)

✅ Real-time Whisper/Saarika v2

✅ Real-time Whisper/Saarika v2

❌ Skipped (text input)

TTS (Text-to-Speech)

✅ OpenAI/ElevenLabs/Sarvam

✅ D-ID handles (if D-ID configured)

❌ Skipped (text output)

Best For

Phone support, hands-free operations

Sales demos, customer reception, training

Web chat, WhatsApp, SMS, email

Setup Complexity

Low (microphone + browser)

Medium (D-ID credentials required)

Low (no extra hardware)

Typical Latency

2–4 seconds end-to-end

3–5 seconds (D-ID processing)

1–2 seconds (streaming)

Cost Profile

Moderate (STT + TTS)

Higher (STT + D-ID avatar + video bandwidth)

Lowest (text-only, single LLM call)


Agent Type 1: Voice Agents

What Is a Voice Agent?

A Voice agent listens to audio input from a microphone, processes it through your configured workflow, and replies with spoken audio.

Real-world scenario: A customer calls your support line. Instead of waiting for a human, they connect to your Voice agent. The agent understands their issue, retrieves the answer from your knowledge base, and explains the solution aloud.

How It Works: The Voice Pipeline

The workflow has 6 key steps:

  1. User Speaks — Audio captured from microphone

  2. Speech-to-Text (STT) — Whisper or Saarika v2 converts audio to text

  3. Intent Detection — LLM classifies what the user is asking

  4. Knowledge Retrieval — Vector search finds relevant docs from your knowledge base

  5. LLM Response Generation — Generates conversational reply using retrieved context

  6. Text-to-Speech (TTS) — OpenAI, ElevenLabs, or Sarvam converts text to audio

  7. Agent Speaks — Audio plays back to user in real-time

Latency: 2–4 seconds end-to-end (STT + retrieval + synthesis all add time)

Voice Agent Settings You Control

When you create a Voice agent, you'll configure:

Setting

Example

Why It Matters

System Prompt

"You are Priya, a support agent for Acme Corp. Be friendly but professional."

Defines the agent's personality and role

Knowledge Base

Upload your FAQ, product docs, troubleshooting guides

Powers the "what to answer"

Scope Topics

["Technical Issues", "Billing", "Refunds"]

Defines what the agent CAN discuss

STT Provider

Whisper (default) or Saarika v2 (Hindi/Tamil/etc.)

Affects accuracy for accented speech

TTS Provider

OpenAI (default), ElevenLabs, Sarvam

Changes voice quality and naturalness

TTS Voice ID

(if ElevenLabs) "Rachel", "Chris", etc.

Specific voice personality

Language

en (default), hi, ta, es, etc.

BCP-47 language tag

Where Voice Agents Shine

Phone support lines — Replace IVR systems with natural conversations
Hands-free operations — Warehouse staff, fieldworkers with headsets
Callback requests — Capture a phone number, call them back later
Appointment scheduling — Book calls, reschedule, send reminders
Multilingual support — Same agent handles English, Hindi, Spanish

Voice Agent Deployment Channels

Channel 1: Web Browser

User visits your website → Clicks "Call our AI agent" button
→ Browser opens WebSocket connection: ws://api.heyadmin.ai/ws/voice/:agentId
→ Microphone + speaker activated → Conversation starts

Channel 2: Phone (Twilio Inbound)

Customer dials your business phone number
→ Twilio receives the call → Forwards audio to: ws://api.heyadmin.ai/ws/twilio/:callId
→ Agent processes the call → Replies with audio
→ Call logged in Sessions tab

Channel 3: Callback Request

In a chat or voice session, user says: "Call me back tomorrow at 2pm"
→ Agent detects intent: callback_request
→ Schedules an outbound call via Twilio at specified time
→ Agent calls the customer → Conversation resumes

Agent Type 2: Video Agents (With D-ID Avatar)

What Is a Video Agent?

A Video agent combines a real-time AI avatar (powered by D-ID) with the full voice agent pipeline. Instead of hearing a voice, the user sees a lip-synced virtual person speaking.

Real-world scenario: A prospect visits your sales website and clicks "Chat with our AI". A professional-looking avatar appears and welcomes them. The avatar listens to their questions, retrieves competitive pricing info from your knowledge base, and responds with lip-synced speech. The prospect feels like they're talking to a real person.

How It Works: Video Agent Architecture

Unlike Voice agents (which just output audio), Video agents layer a visual avatar on top:

Audio Processing Path:

  • User speaks → STT → Intent detection → Knowledge base search → LLM generates text reply

D-ID Avatar Layer (Platform Managed):

  • LLM text reply → D-ID API receives text → Lip-sync synthesis → Avatar speaks with lip-sync

  • WebRTC stream sent directly to browser → User sees animated avatar

Key difference: Video agents skip TTS (OpenAI/ElevenLabs). Instead, D-ID handles all speech synthesis, so the avatar's lips sync perfectly with the words.

The D-ID Architecture

Important: D-ID is fully managed by heyadmin.ai. Here's what that means:

What the Platform Controls

What You Don't Control

D-ID API Key

Which avatar appears

D-ID Agent ID

Avatar voice/language (global setting)

D-ID WebRTC Stream

Avatar customization per agent

Avatar idle-loop video

D-ID API billing

Why? One D-ID account funds all customers. The avatar and voice are consistent across your entire platform for brand unity.

What You DO Control:

  • ✅ Agent's system prompt (what the avatar says)

  • ✅ Knowledge base (what it answers from)

  • ✅ Language tag (en, hi, es, etc.)

  • ✅ Scope topics (what it can discuss)

  • ✅ Webcam analysis (toggle to see user emotion/attention in real-time)

Video Agent Workflow

User speaks + webcam frame captured → Audio processing (STT → Intent → KB → LLM) → Text reply generated → D-ID Avatar API processes text → Lip-sync synthesis begins → WebRTC stream sent to browser → Avatar visible with audio → (Optional) Webcam analysis shows emotion/attention scores

Setting Up a Video Agent

Step 1: Create an agent and select Type: Video

Step 2: Configure like any other agent:

  • System prompt

  • Knowledge base

  • Scope topics

  • Language

Step 3 (Optional): Enable Webcam Frame Analysis

  • Toggle: videoAnalysis: true

  • You'll see real-time emotion/attention scoring in /dashboard/sessions

  • Useful for: sales demo engagement tracking, training feedback

Video Agent Use Cases

Sales & demos — Avatar explains product, answers objections, schedules demo
Customer reception — 24/7 virtual receptionist greets visitors
Onboarding training — Avatar walks new users through your platform
Multilingual sales — Same avatar, different language prompts
Recruitment interviews — Automated initial screening with visual presence
User engagement tracking — Monitor caller attention/emotion in real-time


Agent Type 3: Chat Agents

What Is a Chat Agent?

A Chat agent is text-only — no microphone, no audio, no video. Users type questions and receive streaming text replies.

Think of it as your Voice agent's text sibling: same knowledge base, same LLM logic, zero audio processing.

Real-world scenario: A customer opens your website and types "Do you offer refunds?" into your chat widget. The Chat agent instantly retrieves your refund policy from its knowledge base and types back: "Yes, we offer 30-day refunds for all products..."

How It Works: The Chat Pipeline

Chat agents skip the audio steps entirely:

  • User types message (text input)

  • ✂️ Skip STT — text is already captured

  • Intent detection (classify user goal)

  • Knowledge base search (find relevant docs)

  • LLM streaming (generate response word-by-word)

  • ✂️ Skip TTS — output is text, not audio

  • Streaming text displayed to user

Why Chat Agents Are Fastest: No speech processing overhead = 500ms–2 second responses vs. Voice's 2–4 seconds.

Chat Agent Features

1. Text Streaming

User sees the agent's response appear in real-time, word-by-word (like ChatGPT). Feels fast and responsive.

2. Multi-Turn Conversation

  • Session memory automatically maintained

  • Follow-up questions understood in context

  • Example:

    User: "What's your refund policy?"
    Agent: "30 days, full refund."
    User: "Can I return opened items?"
    Agent: "Yes, but items must be in resalable condition."
    

3. Sources & Follow-Ups (if enabled)

After each reply, show:

  • Sources: "This answer came from: FAQ #12, Returns Policy v2" (with links)

  • Follow-ups: Suggested next questions (powered by LLM)

4. Session Logging

Every chat is logged in /dashboard/sessions with:

  • Full transcript

  • Retrieved knowledge base chunks

  • User thumbs-up/thumbs-down feedback

  • Integration data (if connected to CRM/support)

Chat Agent Channels

Channel 1: Web Chat Widget

<script>embed heyadmin.ai chat widget</script>
→ Small chat bubble in bottom-right corner
→ User clicks → Opens chat window
→ Conversation starts
→ Transcript saved in Sessions

Channel 2: WhatsApp (MCP Adapter)

User sends WhatsApp message to your business number
→ Webhook received: POST /api/webhooks/whatsapp
→ Agent processes message
→ Reply sent back via WhatsApp
→ Conversation logged per phone number

Channel 3: SMS (Twilio)

User texts: "Store hours?"
→ Twilio webhook → Agent processes
→ Reply texted back: "Open 9am–6pm, Mon–Fri"
→ SMS logged in Sessions

Channel 4: Email (via MCP)

Customer emails support@yourcompany.com
→ Email webhook received
→ Agent generates reply email
→ Sent to customer email
→ Logged in Sessions + CRM

Chat Agent Use Cases

Website chat widget — 24/7 instant answers to common questions
WhatsApp support — Customers reach you on their preferred app
SMS support — Quick replies via text for customers without data
Email automation — Inbound emails auto-replied within seconds
Knowledge base search — Customers ask naturally instead of browsing docs
Lead qualification — Chat collects info, routes to sales team
Multiple languages — Text auto-detection, single agent per language


Comparison Matrix: When to Use Which

Scenario

Recommended

Why

Customer support helpline

Voice

Customers call; fast troubleshooting over audio

Sales demo website

Video

Visual presence + voice builds trust

Website FAQ bot

Chat

Text-based, always available, lowest cost

Warehouse operations

Voice

Hands-free audio, staff use headsets

Recruitment screening

Video

Avatar interviewer; record candidate responses

Multilingual chat

Chat

Route by language; no audio synthesis cost

Appointment booking

Voice

Natural conversation; easier to speak dates/times

Training onboarding

Video

Avatar walks through tutorial; engaging visual

Bulk support (1000s/day)

Chat

Scales cheapest; no TTS per request


Decision Tree: Pick Your Agent Type

Quick logic:

  1. How will users interact?

    • They CALL → Voice Agent

    • They VISIT your WEBSITE → Ask: "Do you want a visual avatar?"

      • Yes → Video Agent

      • No → Chat Agent

    • They MESSAGE you (WhatsApp/SMS/Email) → Chat Agent


Shared Intelligence: All Three Types Use the Same Core

While the three agent types have different interfaces, they share identical core intelligence:

┌─────────────────────────────────────────┐
│       SHARED AGENT INTELLIGENCE         │
├─────────────────────────────────────────┤
│  • System Prompt (your brand voice)     │
│  • Knowledge Base (your truth source)   │
│  • Scope Topics (what to answer)        │
│  • Cost Limits (spend guard)            │
│  • Session Memory (context window)      │
│  • Feedback Loop (👍/👎 training)      │
└─────────────────────────────────────────┘
           │
    ┌──────┼──────┐
    ▼      ▼      ▼
 [Voice] [Video] [Chat]

This means:

  • ✅ Same knowledge base powers all channels

  • ✅ System prompt consistency across Voice/Video/Chat

  • ✅ Feedback on chat improves voice agent quality (and vice versa)

  • ✅ Multi-channel agents use identical backend logic


Getting Started: Decision Tree

[See diagram: Agent Type Decision Tree in detail above]


Setup Paths: Start Here

Path 1: Create Your First Voice Agent

  1. Navigate to /dashboard/agents/new

  2. Select Type: Voice

  3. Name your agent (e.g., "Support Bot")

  4. Write a system prompt

  5. Upload knowledge base documents

  6. Click Create

  7. Go to Share tab → copy WebSocket embed code

  8. Embed on your website or share the link

  9. Test with microphone + speakers

  10. Enable feedback (👍/👎)

Path 2: Add a Video Agent

  1. Prerequisites: Same as Voice (system prompt + knowledge base ready)

  2. Navigate to /dashboard/agents/new

  3. Select Type: Video

  4. Video agent inherits D-ID avatar (no config needed)

  5. Configure Language and Scope Topics

  6. (Optional) Enable Webcam Frame Analysis for engagement tracking

  7. Create agent

  8. Deploy to website via Share tab

Path 3: Deploy Chat to Website

  1. Create agent (Voice, Video, or dedicated Chat agent)

  2. Go to /dashboard/agents/:agentId/share

  3. Under Chat Widget, copy the embed code

  4. Paste into your website <head> or before closing </body>

  5. Chat widget appears in bottom-right corner

  6. Customize colors/branding in widget settings

  7. Test in browser


Monitoring & Optimization

All Three Types: Sessions Dashboard

After your agent goes live, visit /dashboard/sessions to see:

Metric

Shown For

Transcript

All types

Latency

Voice (STT time) + Video (D-ID processing)

User Feedback

All types (👍/👎 thumbs icons)

Sources

All types (which KB chunks were used)

Webcam Analysis

Video only (emotion/attention scores)

Errors

All types (out-of-scope rejections, KB gaps)

Cost Tracking

Visit /dashboard/adminCost to see:

Voice: $0.02 per minute (STT + LLM + TTS)
Video: $0.05 per minute (STT + LLM + D-ID avatar)
Chat:  $0.003 per message (LLM only)

Cost limit can be set per month to prevent runaway bills.


Common Questions

Q: Can I switch an agent's type after creation? A: No, agent type is set at creation. If you need to change, create a new agent with the same knowledge base and system prompt, then redirect traffic.

Q: Can one agent be deployed to Voice + Chat + WhatsApp? A: Yes! Create one agent, then deploy via:

  • Voice: Share tab → WebSocket embed

  • Chat: Share tab → Chat widget embed

  • WhatsApp: /api/webhooks/whatsapp webhook (requires phone number setup)

Q: Why does D-ID avatar look the same for all my agents? A: D-ID is platform-managed for consistency. One avatar, one voice, all agents. Your system prompt and knowledge base make each agent unique—not the visual appearance.

Q: Can I use a custom avatar or voice? A: Custom avatars and voices are platform-level features (SUPER_ADMIN only). Contact heyadmin.ai support for custom branding.

Q: Which agent type is cheapest? A: Chat agents. No STT/TTS = lowest API costs. Voice and Video have audio processing overhead.

Q: Do I need to upload knowledge base docs for the agent to work? A: No, but recommended. Without a knowledge base, agents rely only on their system prompt and the LLM's training data. Knowledge base makes answers specific to your business.


Next Steps

  1. Pick your agent type based on your use case (see Decision Tree above)

  2. Create your first agent at /dashboard/agents/new

  3. Upload knowledge base docs that your agent will reference

  4. Write system prompt that defines your agent's personality

  5. Deploy to one channel (web, WhatsApp, or phone)

  6. Monitor sessions in /dashboard/sessions

  7. Collect feedback (👍/👎) to improve agent quality


Summary

Agent Type

Best For

Time to Set Up

Complexity

Voice

Phone support, hands-free ops

10 minutes

Low

Video

Sales demos, visual engagement

15 minutes

Medium

Chat

Website widget, WhatsApp, SMS

5 minutes

Low

All share the same knowledge base, system prompt, and LLM intelligence. The choice is about channel and user interaction style, not about capability.

Start with the agent type that matches your primary channel, then add others later as needed.

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